Dome & Telescope Main Structure
- A hemispherical dome with curved, laterally opening doors (40 m opening) rotating on top of a concrete pier foundation is to house the telescope.
- The dome allows for the complete freedom of the telescope to position itself within the dome whether it be open or closed. Dome rotation is performed by 54 upward facing bogies (rotating more than 4000 T).
- The dome permits observations from zenith to 20 degrees from the horizon. A deployable windscreen protects the telescope from high wind speeds while many louvers increase the ventilation of the internal volume.
- The dome is specified to be air and watertight. Airtightness is critical in minimising the air conditioning load.
- Telescope main structure (telescope mount) provides for coarse pointing and tracking of ~3000T of steel plus all housed units where the fine alignment of the optics and beam steering is done by the optical element control.
- The telescope is an alt-azimuth mount based on the rocking chair concept. Two massive cradles provide the rotation of the altitude axis while two azimuth tracks take the axial loads and allow the telescope to rotate about the zenith.
- Axial and radial hydrostatic bearings and direct drive motors form the baseline for the design.
- The challenge is to provide a stiff enough interface for the primary mirror segments while at the same time not dramatically increasing the weight of the structure or overcomplicating the support.